Upton's correspondence from the period 1878-1880, written primarily to members of his family, is an invaluable source of information about the early stages of the incandescent lamp. The material from the mid-1880s through the 1890s deals primarily with the Edison Lamp Co., of which Upton was general manager. Included are numerous notes and memoranda concerning lamp manufacture. Several undated items at the end of the collection also date from this period. The post-1900 items include a note from Edison about the fire of December 9, 1914, that damaged or destroyed more than half of the buildings at the West Orange laboratory complex; Upton's notes about Edison for a speech at the first Edison Pioneers' meeting in 1918; and a membership list of the Pioneers.

The correspondence and other unbound documents have been arranged in chronological order. Undated documents to which no year could be assigned have been arranged in approximate chronological order at the end of the collection. All but a few items have been selected. The unselected material includes a patent issued to Upton, several speeches and articles unrelated to Edison, photographs, and memorabilia.